Physics: Post your doubts here!

[Cem]

Practical 9702/35 was easy as!!

 

[anonymous123]

Practical 9702/35 was easy as!!

did u get electricity?

 

[confused123]

I - uh - didn't ask for the other answers.

And are you sure you meant to say right AND down, and left AND up instead of right and left OR down and up? Because the former wouldn't make sense. You'd have directions pointing in both, the clockwise and anticlockwise directions. :/

Part of my original question remains unanswered. Why would they behave in a such a way? Are charges supposed to line up parallel to the direction of the field?

well u asked for the 6 b part. :|

i am pretty sure now that the direction of force on the positive charge is towards right parallel with field line, and on the negative charge its towards left because according to my concept that's how a couple of a force is formed. the forces are equal and opposite in direction. the positive one will tend to move right as it get attracted to the negative plate and the negative charge will be attracted towards positive plate i.e on left. what say?

 

[hmlahori]

q.2 b) if u will suspend a plumbline from different positions then you can know the centre of gravity. i mean you need to draw 4 lines from vertices and then find their intersection point, that will be below pivot. it will eventually come to rest because centre of gravity is in line with pivot. no turning effect produce as we are applying force on the pivot line. this is what i got from the question.

4 b ii) lets find the approximate are:2 [1/2 into .3 into 0.08 ] = 0.024 m

note: i converted the speed from cm/s into m/s and divided the graph into two triangles.

s 06) q.2 c) resolving forces horizontally: we can see that F cos a and T cos B are the only two horizontal forces. now just equate them, they must be equal so that the system remains in equilibrium. Fcos a = T cos b

ii ) resolving vertically: there are two forces acting upwards which are F sin a and T sin b , these two upward forces must equal with the downward weight. hence Fsin a + T sin b = W

iii) sum of moments at A) F doesn't contribute as it is acting at the pivot. o moment by force F.
now we know that AC = 2/3 Ab
the upward force is T sin B and downward is W. the distance of W from A in terms of AB is 2/3 , the distance of T sin B is equal to AB from A point. . now the equation becomes 2/3 AB into W = T sin b into AB , which further becomes 2W= 3T sin b. hope that helps.

can you give your opinion on this question b part?

question 4 b basically asks how rod will be in equilibrium. For this to happen the resultant force on the rod must be zero as well as any moments of forces. the two other forces W & T pass through P and so force F must also pass through P. in this way the distance of all the forces together from P will be zero hence they will cancel out the effect of each other and no resultant force or moment about P thus rod in equilibrium.
And thanks for your help!

 

[confused123]

question 4 b basically asks how rod will be in equilibrium. For this to happen the resultant force on the rod must be zero as well as any moments of forces. the two other forces W & T pass through P and so force F must also pass through P. in this way the distance of all the forces together from P will be zero hence they will cancel out the effect of each other and no resultant force or moment about P thus rod in equilibrium.
And thanks for your help!

that's nice. thankyou , how will be the distance from P together of all forces be zero, how will they cancel i mean :/

 

[Jaf]

well u asked for the 6 b part. :|

i am pretty sure now that the direction of force on the positive charge is towards right parallel with field line, and on the negative charge its towards left because according to my concept that's how a couple of a force is formed. the forces are equal and opposite in direction. the positive one will tend to move right as it get attracted to the negative plate and the negative charge will be attracted towards positive plate i.e on left. what say?

Oh wow. Yes, this is it! Thanks so much!

 

[confused123]

Oh wow. Yes, this is it! Thanks so much!

Finally! due to you my concept is refined as well

 

[confused123]

http://www.xtremepapers.com/CIE/International A And AS Level/9702 - Physics/9702_s08_qp_2.pdf
Q.2 b i and ii.

 

[dilchan]

Hey Guys and Gals.... Need a last minute revision notes for AS physics... Check these out...Want more??? Then like me and just ask...Im kinda busy these days..but ill try my best to provide more notes

Unit 1-Quantities and their Measurements​

Unit 2-Motion,Force and Energy​

Unit 3-Electric charge​

Unit 4-Matter​

Unit 4-Atomic physics​

Unit 5-Waves​

 

[confused123]

http://www.xtremepapers.com/CIE/International A And AS Level/9702 - Physics/9702_s08_qp_2.pdf
q.6 b

 

[anonymous123]

9709 s10 23
Q1
±1 digit accuracy means? and in part ii why is the max value 2.08
thx

 

[Oliveme]

Can someone please help me with this question. It's a very small question. Question 5c(i) they haven't told us the directions?
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s10_qp_21.pdf
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s10_ms_21.pdf

Thank you very much!

 

[dilchan]

http://www.xtremepapers.com/CIE/International A And AS Level/9702 - Physics/9702_s08_qp_2.pdf
q.6 b

Switch closed means the power pass through that part of circuit(through the closed switch) and as the heating elements are similar they all have the same constant resistance. So calculate the parallel resistances and thereby calculate the TOTAL RESISTANCE of the heating elements in circuit where the current passes. The calculate the power using the total resistance. The power supply is providing a constant emf of 240v. Contact me for more details.

 

[sidbloom]

i need to know what is exactly meant by shorted lamp..........
by the name i think it means that the lamp is fussed but when i searched it i got really confused....so i want to know what is the exact meaning
thanks ^_^

 

[rami-mustang_gt]

PLEASE HELP ME
WHAT ARE THE CONDITIONS FOR DIFFRACTION GRATING ??

 

[rami-mustang_gt]

YOU HAVE SHORTED AND BROKEN LAMPS.
WHEN THERE IS A BREAK IN THE FILAMENT OF THE LAMP, R=INFINITE ohms
WHEN THE FILAMENT MELTS DOWN TO GIVE THICK SHORT WIRE R=0 ohms

 

[confused123]

th

Switch closed means the power pass through that part of circuit(through the closed switch) and as the heating elements are similar they all have the same constant resistance. So calculate the parallel resistances and thereby calculate the TOTAL RESISTANCE of the heating elements in circuit where the current passes. The calculate the power using the total resistance. The power supply is providing a constant emf of 240v. Contact me for more details.

thanks a lot man, but can you write a reason for every calculation in the table.

 

[confused123]

PLEASE HELP ME
WHAT ARE THE CONDITIONS FOR DIFFRACTION GRATING ??

please turn of the caps lock!

in order to observe diffraction, width of the opening or gap should be comparable with the wavelength of waves passing through.

 

[anonymous123]

Hey Guys and Gals.... Need a last minute revision notes for AS physics... Check these out...Want more??? Then like me and just ask...Im kinda busy these days..but ill try my best to provide more notes

Unit 1-Quantities and their Measurements​

Unit 2-Motion,Force and Energy​

Unit 3-Electric charge​

Unit 4-Matter​

Unit 4-Atomic physics​

Unit 5-Waves​

more

 

[raamish]

Wow the notes are awsum more please )